GEOLOGY
Geology as a modern science
Geology has traditionally been considered the science (the body of descriptions
and explanations) that deals with the earth. Of late, with the exploration
of the solar system, its scope has widened, and has come to include other
planets and objects.
Although relatively recent, the birth and growth of geology parallels
that of other sciences. It did not emerge as a cohesive science (i.e. a
consistent body of descriptions and explanations as opposed to a collection
of practical ideas and techniques) until the concept of a real, regular,
reasonable and consistent nature was applied to the earth. Most would agree
that that happened at the end of the XVIIIth Century, when a Scotsman named
James Hutton (1726-1797), formulated the doctrine
of uniformitarianism. In brief, this
doctrine states that "the present is the key to the past."
Prior to uniformitarianism, geologic change was, with few exceptions,
viewed as catastrophic, due to sudden, random events such as the Great
Flood of Noah. The central problem with catastrophism
is that this model does not allow events to be analyzed logically. It denies
an orderly progression of events. Because it considers the geologic record
to be an accumulation of unpredictable events, such a point of view closes
the past to investigation and the future to prediction.
In contrast, uniformitarianism asserts that the same laws which operate
today also operated in the past. Therefore, the present earth's appearance
and behavior is the result of past events. This concept allows us to understand
the earth and, like Janus (the Roman god of doors and gates represented
by a head with two faces), see and understand the past and predict the
future.
With uniformitarianism, Hutton provided the first
global model for geology, as Newton's idea of force had done for
physics and astronomy, Dalton’s notion of the atom for chemistry, and as
Darwin's natural selection would do for biology. Hutton stated that when
we look at the earth, "we find no vestige of a beginning, no prospect of
an end." This concept of an ancient, but consistently changing earth, obeying
immutable chemical and physical laws, is a legacy and foundation upon which
generations of geologists have relied to gain an ever better understanding
of our world.
The story of the Earth is intertwined with the story of the Solar System.
We are, of course, the third planet outward to orbit our sun, a smallish
star whose proper Latin name is Sol. |